The subject matter disclosed herein relates to porous membranes, such as nitrocellulose membranes, and, more particularly, to the formation of patterns on and with such membranes.
Porous membranes may be used as substrate materials for assays, including medical assays or environmental assays. For example, a porous membrane may include some or all of the assay components, e.g., antibodies or binding agents, that react with a sample and provide an output. In the example of a pregnancy test, the porous material is placed in contact with the sample fluid, which may then flow laterally along the porous membrane to contact the assay materials disposed on or within the porous membrane. Depending on the presence or absence of a particular compound, such as hCG, the sample will react with the assay components in the porous membrane to provide different visual outputs, depending on if the sample is from a pregnant or non-pregnant patient. In such an example, the assay components are arranged along the lateral flow path of the porous membrane. For more complicated assays, more complex flow paths and patterns may be involved. However, such patterns may be difficult to form, particularly in repeating patterns on larger sheets that are subsequently cut into single strips for individual use.